[600MRG] Preliminary Earth Loop Results

[William E. Isakson]

This is not really surprising John.  Considering 600 meter wavelengths, an
antenna laying on the ground is in essence no different from one 30 feet
up.   Also, in Inverness we used to put an 80 meter dipole on the ground to
communicate "over the hill" where no one could reach with any band because
of the mountain shadowing.  The signal from the dipole went straight up and
bounced back into every valley and crevice.  The same trick was used in
Iraq where the antennae were actually buried under the sand.   Sand is not
very conductive, but even your more normal ground is not very conductive in
comparison to the metal in your antenna.
Bill
AC6QV

--------


Bill Isakson
Roseburg, Oregon USA
bill.isakson at gmail.com




On Thu, Sep 26, 2013 at 4:53 AM, John Molnar <wa3etd at gmail.com> wrote:

> All,
> Several days ago I experienced a wind gust that knocked my tripod mounted
> 10' diameter shielded magnetic loop to the ground, it landed flat still
> pointed NE -SW.
> Interestingly enough, I still had multiple WSPR spots from John WG2XIQ all
> night. (2395 KM path).  Originally the bottom (preamp end) of the loop is
> about 6' above ground level.  The grass was soaked from the storm.
>
> Obviously curious, I duplicated the "experiment".
> I constructed an identical 10' loop (RG-6) and built an identical
> preamplifier and bias Tee.  This was setup on the grass, about 30' from the
> vertical loop.  I used two identical laptops running WSPR 2.0.  Identical
> receivers,
> FT-857 and FT-897 (same guts) were used. AGC off.  There is no common
> component shared by the two receive systems.  They are totally independent.
>
> The test commenced last evening.  XIQ was the only WSPR station
> transmitting in the USA, I stayed RX only.  The vertical loop reported as
> WG2XKA, the grass mounted earty loop reported as WA3ETD.
>
> As XIQ reported, the earth loop drew "first blood".  Over the course of the
> evening both loops reported, the best spot of XIQ was -22, reported by both
> loop stations.  In several cases, the earth loop indicated a better spot by
> several dB.  The ground here is currently wet and the night dew was very
> heavy.  Very weak (-29, -30) were also reported by both loops.
>
> I have yet to quantify all the data, but results are encouraging and the
> tests will continue.
>
> For anyone interested, the data can be recovered on WSPRNET, entering the
> appropriate "reporter" calls listed above.
>
> John WG2XKA / WA3ETD
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